Curved spacer and inserter

ABSTRACT

The present teachings provide one or more surgical implements for repairing damaged tissue, such as in the case of a spinal fixation procedure. A cross connector system for use during a spinal fixation procedure is provided. The system includes at least one bridge defining a coupling bore and having a pair of downwardly extending arms for coupling to a first fastener. The system includes a contoured bar having a first end offset from a second end, and a bore having a central axis. The system includes an expansion ring received within the bore, and a locking device received through the expansion ring and the coupling bore. The locking device is operable in a first state in which the contoured bar is movable about the central axis of the bore and in a second state in which the contoured bar fixed relative to the central axis of the bore.

INTRODUCTION

In general, the human musculoskeletal system is composed of a variety oftissues including bone, ligaments, cartilage, muscle, and tendons.Tissue damage or deformity stemming from trauma, pathologicaldegeneration, or congenital conditions often necessitates surgicalintervention to restore function. Surgical intervention can include anysurgical procedure that can restore function to the damaged tissue,which can require the use of one or more orthopedic prosthesis, such asorthopedic nails, screws, implants, etc., to restore function to thedamaged tissue. In certain instances, such as in a spinal fusionprocedure, it can be desirable to insert an implant into anintervertebral disc space to restore disc height and stabilize thevertebrae for long term spinal fusion.

The present teachings relate to a spinal implant and instrument systemfor use in a surgical procedure, such as a spinal fusion procedure, andmore specifically relates to a curved spacer and an inserter forpositioning the curved spacer within the anatomy.

SUMMARY

Provided is an instrument for inserting an interspinous spacer. Theinstrument can include an elongated body have a proximal end, a distalend and a first passage therebetween. The instrument can further includea handle at the proximal end of the body having a second passagetherebetween. The instrument can include a rod received through thefirst passage and the second passage. The rod can be movable relative tothe elongated body and the handle. The rod can have a distal end adaptedto be coupled to the interspinous spacer. The instrument can include afirst curved surface positioned adjacent to the distal end of theelongated body and adapted to contact the interspinous spacer. Theinstrument can also include a second curved surface positioned adjacentto the distal end of the elongated body opposite the first curvedsurface. The second curved surface can be adapted to contact theinterspinous spacer.

Further provided is an instrument for inserting an interspinous spacer.The instrument can include an elongated body have a proximal end and adistal end, and a handle coupled to the proximal end of the body havinga passage therebetween. The instrument can include a first arm movablerelative to the elongated body, which can be received at least partiallywithin the passage. The first arm can have a proximal end and a distalend. The distal end can be adapted to contact the interspinous spacer.The proximal end of the first arm can define at least one engagementfeature. The instrument can include a second arm movable relative to theelongated body, which can be received at least partially within thepassage. The second arm can be positioned relative to the first armabout the elongated body. The second arm can have a proximal end and adistal end. The distal end can be adapted to contact the interspinousspacer. The instrument can include a drive system received at leastpartially within the handle, which can interact with the firstengagement member such that movement of the drive system moves the firstarm reciprocally relative to the second arm.

Also provided is an instrument for inserting an interspinous spacer. Theinstrument can include an elongated body have a proximal end, a distalend and a first passage. The instrument can include a handle coupled tothe proximal end of the body having a second passage therebetween. Theinstrument can also include a first arm slidable relative to theelongated body and the handle. The first arm can have a proximal endreceived within the second passage and a distal end adapted to contactthe interspinous spacer. The distal end can be positioned along theelongated body. The proximal end of the first arm can define a pluralityof threads and a link feature. The instrument can include a second armslidable relative to the elongated body and the handle. The second armcan have a proximal end received within the second passage and a distalend adapted to contact the interspinous spacer. The distal end can bepositioned along the elongated body. The second arm can be positionedopposite to the first arm. The proximal end of the second arm can have alink feature. The instrument can include a driver received within thesecond passage defining a plurality of threads threadably engagable withthe plurality of threads of the first arm. The driver can be rotatablewithin the second passage to cause translation of the first arm relativeto the elongated body and the handle. The instrument can include apivoting link retained within the second passage and in communicationwith the link feature of the first arm and the link feature of thesecond arm so that the translation of the first arm causes reciprocalmotion of the second arm.

Still yet also provided is an instrument for inserting an implant havinga handle defining a bore longitudinally extending therethrough. A rodpasses through the bore. The rod has a proximal end on a proximal sideof the handle and a distal end on a distal side of the handle. Thedistal end is adapted to releasably engage the implant. A knob iscarried at the proximal end of the rod for rotating the rod relative tothe housing. The knob is coupled to the rod such that the knob isdisplaceable relative to the rod in a direction toward the distal end ofthe rod.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present teachings.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present teachings in any way.

FIG. 1 is a perspective view of an exemplary curved spacer and inserterfor use in a spinal fixation procedure according to the presentteachings;

FIG. 2 is an environmental view of the curved spacer of FIG. 1positioned between endplates of adjacent vertebral bodies according tothe present teachings;

FIG. 3 is a schematic environmental illustration of the inserter of FIG.1 positioning the curved spacer within the anatomy;

FIG. 4 is a perspective view of the curved spacer of FIG. 1;

FIG. 5 is a top view of the curved spacer of FIG. 1;

FIG. 6 is a side view of the curved spacer of FIG. 1;

FIG. 7 is an end view of the curved spacer of FIG. 1;

FIG. 8 is a cross-sectional view of the curved spacer of FIG. 1, takenalong line 8-8 of FIG. 7;

FIG. 9 is a perspective, partially broken away view of the curved spacerof FIG. 1, illustrating an exemplary coupling portion of the curvedspacer;

FIG. 10 is an end view of the curved spacer and inserter of FIG. 1;

FIG. 11 is an exploded view of the inserter of FIG. 1;

FIG. 12 is a cross-sectional view of the curved spacer and inserter ofFIG. 1, taken along line 12-12 of FIG. 10;

FIG. 13 is a cross-sectional view of the curved spacer and inserter ofFIG. 1, taken along line 13-13 of FIG. 10;

FIG. 14 is a schematic illustration of a portion of an exemplary drivesystem for use with the inserter of FIG. 1;

FIG. 15 is a partial cross-sectional view of the curved spacer andinserter of FIG. 1, illustrating the curved spacer positioned at a firstangle relative to the inserter;

FIG. 16 is a partial cross-sectional view of the curved spacer andinserter of FIG. 1, illustrating the curved spacer positioned at asecond angle relative to the inserter;

FIG. 17 is perspective view of another exemplary inserter for use withthe curved spacer according to the present teachings;

FIG. 18 is an exploded view of the inserter of FIG. 17;

FIG. 19 is an end view of the inserter of FIG. 17;

FIG. 20 is a cross-sectional view of the curved spacer and inserter ofFIG. 17, taken along line 20-20 of FIG. 19;

FIG. 21 is a cross-sectional view of the curved spacer and inserter ofFIG. 17, taken along line 21-21 of FIG. 19;

FIG. 22 is perspective view of another exemplary inserter for use withthe curved spacer according to the present teachings;

FIG. 23 is an exploded view of the inserter of FIG. 22;

FIG. 24 is an end view of the inserter of FIG. 22;

FIG. 25 is a cross-sectional view of the curved spacer and inserter ofFIG. 22, taken along line 25-25 of FIG. 24;

FIG. 26 is a cross-sectional view of the curved spacer and inserter ofFIG. 22, taken along line 26-26 of FIG. 24;

FIG. 27 is a detail view of a portion of the inserter of FIG. 22 coupledto the curved spacer such that the curved spacer is at a first exemplaryangle relative to the inserter;

FIG. 28 is a detail view of a portion of the inserter of FIG. 22 coupledto the curved spacer such that the curved spacer is at a secondexemplary angle relative to the inserter;

FIG. 29 is perspective view of another exemplary inserter for use withthe curved spacer according to the present teachings;

FIG. 30 is an exploded view of the inserter of FIG. 29;

FIG. 31 is an end view of the inserter of FIG. 29;

FIG. 32 is a cross-sectional view of the curved spacer and inserter ofFIG. 29, taken along line 32-32 of FIG. 31;

FIG. 33 is a detail cross-sectional view of a locking portion of theinserter of FIG. 29 taken from A of FIG. 32;

FIG. 34 is a detail view of a portion of the inserter of FIG. 29 coupledto the curved spacer such that the curved spacer is at a first exemplaryangle relative to the inserter;

FIG. 35 is perspective view of another exemplary inserter for use withthe curved spacer according to the present teachings;

FIG. 36 is an exploded view of the inserter of FIG. 35;

FIG. 37 is a side view of the inserter of FIG. 35;

FIG. 38 is a cross-sectional view of the curved spacer and inserter ofFIG. 35, taken along line 38-38 of FIG. 37; and

FIG. 39 is a detail cross-sectional view of a locking portion of theinserter of FIG. 35 taken from B of FIG. 38.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is notintended to limit the present teachings, application, or uses. It shouldbe understood that throughout the drawings, corresponding referencenumerals indicate like or corresponding parts and features. Although thefollowing description is related generally to a curved spacer andinserter for use in an anatomy to for a spinal fusion procedure, it willbe understood that the curved spacer and inserter as described andclaimed herein can be used in any appropriate surgical procedure, suchas in a minimally invasive procedure. Therefore, it will be understoodthat the following discussions are not intended to limit the scope ofthe present teachings and claims herein.

With reference to FIGS. 1-16, a curved spacer 10 and an exemplaryinserter 12 is shown. The curved spacer 10 may be particularly adaptedfor spinal fusion procedures, such as a trans-foraminal intervertebralfusion procedure. Various aspects of the present teachings, however, mayhave application for other procedures. In certain applications, withreference to FIG. 2, the curved spacer 10 can be positioned within anintervertebral disc space D, between adjacent vertebral bodies V torestore disc height and stabilize the vertebrae for long-term spinalfusion. It should be noted that although a single curved spacer 10 willbe described and illustrated herein as being positioned within anintervertebral disc space, multiple curved spacers 10 could be used invarious locations along the spinal column depending upon the selectedprocedure. As will be discussed herein, the curved spacer 10 can beinserted into the anatomy via the inserter 12 (FIG. 3). The curvedspacer 10 can include a main body 14 and a coupling portion 16.

The main body 14 of the curved spacer 10 can be shaped to conform to theanterior curve of the vertebral body V (FIG. 3). In one example, themain body 14 can have a kidney shape, however, the main body 14 couldhave any selected shape. The main body 14 can be comprised of a suitablebiocompatible material, such as a biocompatible metal, polymer orceramic. For example, the main body 14 can be composed of polyetherether ketone (PEEK), but the main body 14 could also be formed oftitanium. With reference to FIGS. 4-6, the main body 14 can include afirst or distal end 18, a second or proximal end 20, a first side 22, asecond side 24, a first or superior surface 26, a second or inferiorsurface 28 (FIG. 6) and a cavity 30.

With reference to FIGS. 6 and 7, the distal end 18 can include a firstbeveled surface 32 generally opposite a second beveled surface 34. Thefirst beveled surface 32 and second beveled surface 34 can assist indistracting the adjacent vertebral bodies V during the insertion of thecurved spacer 10, and can assist in navigating the curved spacer 10through the anatomy. The distal end 18 can also include a recess 36. Therecess 36 can receive at least one radiopaque marker 38. The at leastone radiopaque marker 38 can enable an operator to determine thelocation of the distal end 18 using a suitable imaging device, such as afluoroscope, etc.

With reference to FIG. 4, the proximal end 20 can be substantiallyopposite the distal end 18. The proximal end 20 can be generally curvedabout a pivot axis P. The proximal end 20 can include a coupling bore 40and a pocket 42. The coupling bore 40 can receive part of the couplingportion 16 to couple the coupling portion 16 to the main body 14. Thecoupling bore 40 can be defined about the pivot axis P, from thesuperior surface 26 to the inferior surface 28.

With reference to FIGS. 8 and 9, the pocket 42 can receive part of thecoupling portion 16 to couple the coupling portion 16 to the main body14. The pocket 42 can be defined between the superior surface 26 and theinferior surface 28 (FIG. 9). The pocket 42 can be formed to be incommunication with a portion of the coupling bore 40. The pocket 42 canenable the coupling portion 16 to move or pivot about the pivot axis P aselected amount of degrees. In one example, with reference to FIG. 8,the pocket 42 can be defined along an arc A of about 35 degrees to about75 degrees. Thus, the coupling portion 16 can move or pivot about thepivot axis P from about 35 degrees to about 75 degrees. The pocket 42can include a first rounded edge 42 a and a second rounded edge 42 b.The first rounded edge 42 a and the second rounded edge 42 b cancooperate with the inserter 12 to enable the curved spacer 10 to moverelative to the inserter 12.

With reference to FIG. 4, the first side 22 can be generally oppositethe second side 24, and can be defined between the distal end 18 and theproximal end 20. The first side 22 can be substantially arcuate, and inone example, can be generally concave. With reference to FIG. 2, thefirst side 22 can have a height H1, which can be less than a height H2of the second side 24. The difference in the heights H1, H2 can enablethe main body 14 to have a wedge-like shape. In one example, the heightH2 can comprise a height of the curved spacer 10. The height H2 can varyso that the curved spacer 10 can be provided with various heights. Inone example, the height H2 can range from about 20 millimeters (mm) toabout 50 millimeters (mm). The second side 24 can be defined between thedistal end 18 and the proximal end 20. The second side 24 can have theheight H2, and can be substantially arcuate in shape. In one example,the second side 24 can be generally concave.

The superior surface 26 can be defined between the distal end 18 and theproximal end 20, and can be opposite the inferior surface 28. Thesuperior surface 26 can contact an endplate E of an adjacent vertebralbody V. The superior surface 26 can include a texture 44. The texture 44can resist expulsion of the main body 14 from between adjacent vertebralbodies V and can resist motion of the main body 14 relative to theadjacent vertebral bodies. In one example, the texture 44 can comprise aplurality of teeth, which can bite into the adjacent vertebral bodies.It should be noted, however, that any suitable texture could beemployed, such as one or more protrusions, grooves, etc. Further, asuitable coating could be applied as the texture 44. The inferiorsurface 28 can be defined between the distal end 18 and the proximal end20. The inferior surface 28 can contact an endplate E of an adjacentvertebral body V. The inferior surface 28 can include the texture 44. Itshould be noted that although not illustrated herein, the texture 44 onthe inferior surface 28 could be different than the texture 44 on thesuperior surface 26, if desired.

With reference to FIG. 4, the cavity 30 can be defined through the mainbody 14 from the superior surface 26 to the inferior surface 28.Generally, the cavity 30 can be formed between the first side 22 and thesecond side 24, and between the distal end 18 and the proximal end 20.The cavity 30 can facilitate bone in-growth, and can be used to holdgraft material.

The coupling portion 16 can include a coupling body 46 and a pin 48. Thecoupling portion 16 can be composed from any suitable biocompatiblematerial, such as biocompatible metal, polymer or ceramic. In oneexample, the coupling portion 16 can be comprised of titanium. Thecoupling body 46 can be sized to be received within and movable relativeto the pocket 42. With reference to FIGS. 8 and 9, the coupling body 46can include a first or distal end 50, a second or proximal end 52, afirst side 54, a second side 56, a first or superior surface 58 (FIG. 9)and a second or inferior surface 60 (FIG. 9).

With reference to FIG. 8, the distal end 50 can be generally rounded tomate with the shape of the pocket 42. The distal end 50 can include athroughbore 62. The throughbore 62 can be defined frown the u errorsurface 58 to the inferior surface 60. The throughbore 62 can receivethe pin 48 to couple the coupling body 46 to the main body 14.

Referring to FIG. 9, the proximal end 52 can be substantially square orrectangular. With reference to FIG. 8, the proximal end 52 can include acounterbore 64. The counterbore 64 can be defined through the proximalend 52 through a portion of the throughbore 62 of the distal end 50. Thecounterbore 64 can be substantially perpendicular to the throughbore 62.The counterbore 64 can include a plurality of threads 64 a. Theplurality of threads 64 a can enable the coupling portion 16 to bethreadably engaged with the inserter 12, as will be discussed in greaterdetail herein.

With regard to FIG. 8, the first side 54 of the coupling body 46 can beopposite the second side 56. The first side 54 and second side 56 caneach be substantially flat with rounded corners. The first side 54 andthe second side 56 can contact a respective rounded edge 42 a, 42 b ofthe pocket 42 to limit the motion of the coupling portion 16 relative tothe main body 14. The superior surface 58 can be opposite the inferiorsurface 60. With reference to FIG. 9, the superior surface 58 andinferior surface 60 can each be generally flat to support verticalcompressive loads placed on the main body 14.

The pin 48 can be sized to be received through the coupling bore 40 andthe throughbore 62 of the coupling body 46. Thus, the pin 48 can couplethe coupling body 46 to the main body 14. The pin 48 can be generallycylindrical, and can be press-fit into the main body 14, if desired. Thepin 48 can enable the coupling body 46 to move or pivot relative to themain body 14 about the pivot axis P.

With reference to FIG. 1, the inserter 12 can be used to navigate andposition the curved spacer 10 within the anatomy. The inserter 12 can becomposed of any biocompatible material, such as a biocompatible metal orpolymer. In one example, the inserter 12 can comprise an active angleinserter, which can enable a user to select a desired angle for thecurved spacer 10 relative to the inserter 12, as will be discussed. Byallowing the user to select the angle for the curved spacer 10 relativeto the inserter 12 throughout the procedure, the user can betternavigate through the specific patient anatomy. The inserter 12 cancomprise an attachment system 66, an active angle system 68 and ahousing 70.

With regard to FIG. 11, the attachment system 66 can couple the curvedspacer 10 to the inserter 12. The attachment system 66 can include a rod72 and a knob 74. The rod 72 can include a first or distal end 76 and asecond or proximal end 78. The distal end 76 of the rod 72 can have adiameter D1, which can be less than a diameter D2 of the proximal end78. The diameter D1 can be sized to enable the distal end 76 to bereceived within a portion of the housing 70. The distal end 76 caninclude a threaded portion 80. The threaded portion 80 can be formed ata distalmost end 76 a. The threaded portion 80 can include a pluralityof threads 80 a, which can threadably engage a plurality of threads 46 aof the coupling portion 16 to couple the curved spacer 10 to theinserter 12, as best shown in FIG. 12.

With reference back to FIG. 11, the proximal end 78 of the rod 72 canhave the diameter D2, which can be sized to be received within anotherportion of the housing 70. The proximal end 78 can also include adiameter D3 at a proximalmost end 78 a and a groove 79. The diameter D3can be sized to enable the knob 74 to be press-fit onto the proximal end78 of the rod 72. As will be discussed, the groove 79 can receive aportion of the housing 70 to assist in retaining the rod 72 within thehousing 70.

With regard to FIGS. 12 and 13, the knob 74 can enable the user torotate the rod 72 to couple or uncouple the curved spacer 10 from theinserter 12. The knob 74 can include a bore 82 and a graspable portion84. The bore 82 can be coupled to the proximalmost end 78 a of the rod72, via a press-fit, for example. Alternatively, a mechanical fastenercould be used to couple the knob 74 to the rod 72. The graspable portion84 can provide a surface for the user to manipulate the knob 74.Generally, the knob 74 can be rotated in one direction to thread thethreaded portion 80 into engagement with the coupling portion 16 of thecurved spacer 10 to couple the curved spacer 10 to the inserter 12. Theknob 74 can be rotated in an opposite direction to remove the threadedportion 80 from the coupling portion 16 to disengage the curved spacer10 from the inserter 12.

Referring to FIG. 11, the active angle system 68 can enable the curvedspacer 10 to be moved relative to the inserter 12. In one example, theactive angle system 68 can include a first or active arm 86, a second orpassive arm 88, a drive system 90 and an activation device 92. Theactive arm 86 and the passive arm 88 can operate in a reciprocal motionto change the angle of the inserter 12, as will be discussed herein.

The active arm 86 can have a first or distal end 94 and a second orproximal end 96. The distal end 94 can contact the curved spacer 10 andtransmit axial load or impact from the user to the curved spacer. Withreference to FIG. 12, the distal end 94 can define a curved surface 98.The curved surface 98 can remain in contact with the pocket 42 when theinserter 12 is coupled to the inserter 12. In one example, the curvedsurface 98 can move or slide along the first rounded edge 42 a of thepocket 42 to assist in moving the curved spacer 10 relative to theinserter 12. The curved surface 98 can be generally smooth.

With reference to FIG. 11, the proximal end 96 can have a thickness,which can be greater than a thickness of the distal end 94. Theincreased thickness of the proximal end 96 can define a shoulder 100,With reference to FIG. 12, the shoulder 100 can contact a portion of thehousing 70 to define a range of linear motion for the active arm 86. Theproximal end 96 can also include a first driver engagement feature 102and a linkage feature 103. The driver engagement feature 102 cancooperate with the drive system 90 to enable the active arm 86 to moverelative to the housing 70. The driver engagement feature 102 cancomprise a partial thread 102 a and a cup-shaped recess 102 b. Thepartial thread 102 a can engage the drive system 90 to move the activearm 86 relative to the housing 70. The cup-shaped recess 102 b can beconfigured to match a major diameter of the drive system 90 so that theproximal end 96 of the active arm 86 can be positioned around a portionof the drive system 90.

The linkage feature 103 can contact a portion of the drive system 90 toenable the transfer of motion between the active arm 86 and the passivearm 88, In one example, the linkage feature 103 can comprise a circularprojection, which can extend outwardly from a surface of the active arm86. The linkage feature 103 can be formed between the curved surface 98and the proximal end 96.

With reference to FIG. 11, the passive arm 88 can have a first or distalend 104 and a second or proximal end 106. The passive arm 88 can move ina direction opposite the active arm 86 in a reciprocal motion. Thepassive arm 88 is generally not directly driven by the drive system 90.The distal end 104 can contact the curved spacer 10 and transmit axialload or impact from the user to the curved spacer. With reference toFIG. 12, the distal end 104 can define a curved surface 108. The curvedsurface 108 can be generally smooth, and can be substantially a mirrorimage of the curved surface 98. The curved surface 108 can remain incontact with the pocket 42 when the inserter 12 is coupled to the curvedspacer 10, In one example, the curved surface 108 can move or slidealong the second rounded edge 42 b of the pocket 42 to assist in movingthe curved spacer 10 relative to the inserter 12.

The proximal end 106 can have a thickness, which can be greater than athickness of the distal end 104. The increased thickness of the proximalend 106 can define a shoulder 110. With reference to FIG. 12, theshoulder 110 can contact a portion of the housing 70 to define a rangeof linear motion for the passive arm 88. The proximal end 106 can alsoinclude a cut-out 112 and a linkage feature 113. The cut-out 112 canenable the passive arm 88 to be retained next to the drive system 90without engaging the drive system 90. The cut-out 112 can comprise asmooth circular pocket, which can be sized to fit around a portion ofthe drive system 90.

The linkage feature 113 can contact a portion of the drive system 90 toenable the transfer of motion between the active arm 86 and the passivearm 88. In one example, the linkage feature 113 can comprise a circularprojection, which can extend outwardly from a surface of the passive arm88. The linkage feature 113 can be formed between the curved surface 108and the proximal end 106.

With reference to FIG. 11, the drive system 90 can include a driver 114and a pivoting link 116. The driver 114 can drive or move the active arm86 relative to the housing 70. A pivoting link 116 can transmit thedriving force of the active arm 86 to the passive arm 88 and can movethe passive arm 88 in the opposite direction. The driver 114 cancomprise a generally cylindrical shaft, with a first or distal end 118and a second or proximal end 120 The driver 114 can be cannulated, toreceive the rod 72 therethrough. The distal end 118 can include adriving feature 122. The driving feature 122 can include a plurality ofthreads 122 a, which can engage the driver engagement feature 102 of theactive arm 86.

Referring to FIG. 12, the proximal end 120 can include a coupling bore124. The coupling bore 124 can receive a pin 125 to couple theactivation device 92 to the driver 114. The movement or rotation of theactivation device 92 can cause the movement or rotation of the driver114. The movement or rotation of the driver 114 can cause the movementor translation of the active arm 86 relative to the housing 70.

The pivoting link 116 can transfer the motion of the active arm 86 tothe passive arm 88, and can cause the passive arm 88 to move in adirection opposite the active arm 86. With reference to FIGS. 11, 13 and14, the pivoting link 116 can include an annular projection 126 (FIG.13), an active arm feature or notch 128 (FIGS. 11 and 14) and a passivearm feature or notch 130 (FIGS. 11 and 14). With regard to FIG. 13, theannular projection 126 can be received within a portion of the housing70 to movably or pivotally couple the pivoting link 116 to the housing70. Referring to FIG. 14, the active arm notch 128 can be shaped toreceive the linkage feature 103 of the active arm 86 so as to be incommunication with the linkage feature 103. In one example, the activearm notch 128 can be generally U-shaped to receive the annularprojection of the linkage feature 103. The U-shape of the active armnotch 128 can enable the pivoting link 116 to move or pivot about thelinkage feature 103 with the movement of the active arm 86 and canprevent the disengagement of the pivoting link 116 and the active arm86.

The passive arm notch 130 can be positioned generally opposite theactive arm notch 128. The passive arm notch 130 can be shaped to receivethe linkage feature 113 of the passive arm 88. In one example, thepassive arm notch 130 can be generally U-shaped to receive the annularprojection of the linkage feature 113 so as to be in communication withthe linkage feature 113. The U-shape of the passive arm notch 130 canenable the pivoting link 116 to move or pivot about the linkage feature113 of the passive arm 88 to drive the passive arm 88 in a directionopposite the active arm 86 with the movement of the active arm 86. TheU-shape can also prevent disengagement between the linkage feature 113and the pivoting link 116.

With reference to FIGS. 11 and 12, the activation device 92 can becoupled to the driver 114. The activation device 92 can include a bore132, a lip 133, a bore 134 and a graspable portion 136. The bore 132 canreceive the proximal end 120 of the driver 114 and can enable the rod 72to pass through the activation device 92 at a proximalmost end 132 a(FIG. 12). The lip 133 can be formed annularly about the activationdevice 92, adjacent to the bore 132, and can facilitate coupling theactivation device 92 to the housing 70. The bore 134 can be defined in adirection substantially perpendicular to the bore 132 and can be incommunication with the bore 132.

Generally, with regard to FIG. 12, the distal end 118 of the driver 114can be received within the bore 132 so that the coupling bore 124 iscoaxially aligned with the bore 134. The pin 125 can pass through thebore 134 and the coupling bore 124 to couple the activation device 92 tothe driver 114. The graspable portion 136 can provide a gripping surfacefor allowing the user to manipulate or rotate the activation device 92.The manipulation or rotation of the activation device 92 can move orrotate the driver 114, which in turn, can cause the active arm 86 tomove or translate in a first direction and the passive arm 88 to move ortranslate in a second direction, opposite the first direction. Themovement of the active arm 86 and the passive arm 88 can cause thecurved spacer 10 to move relative to the inserter 12, as will bediscussed herein.

With reference to FIG. 11, the housing 70 can enclose at least a portionof the attachment system 66 and the active angle system 68. The housing70 can also provide a graspable portion for the user. The housing 70 caninclude a first or distal portion 140 and a second or proximal portion142. The distal portion 140 of the housing 70 can be an elongated body.The distalmost end 140 a of the distal portion 140 can include a firstcurved surface 144 a opposite a second curved surface 144 b. The firstcurved surface 144 a and the second curved surface 144 b can correspondto a shape of the proximal end 20 of the curved spacer 10. With regardto FIGS. 11 and 12, the distal portion 140 can include a first arm guide146, a second arm guide 148, a passage or cannulated bore 150 (FIG. 12)and a coupling portion 152.

Referring to FIG. 12, the first arm guide 146 can be positioned oppositethe second arm guide 148. The first arm guide 146 and the second armguide 148 can slidably receive a respective one of the active arm 86 andpassive arm 88. The cannulated bore 150 can be defined through thedistal portion 140. The cannulated bore 150 can receive the proximal end78 of the rod 72.

With reference to FIGS. 11 and 13, the coupling portion 152 can couplethe distal portion 140 to the proximal portion 142. The coupling portion152 can comprise a first flat portion 152 a opposite a second flatportion 152 b. The first flat portion 152 a and the second fiat portion152 b can cooperate with the proximal portion 142 to prevent therelative rotation of the distal portion 140 relative to the proximalportion 142. Each of the first flat portion 152 a and the second flatportion 152 b can include a flange 153. The flange 153 can cooperatewith a portion of the housing 70 to assist in coupling the couplingportion 152 to the housing 70 (FIG. 13).

The proximal portion 142 can enclose the drive system 90, and can becoupled to the distal portion 140. With reference to FIG. 11, theproximal portion 142 can include a first handle portion 154, a secondhandle portion 156, a handle retaining portion 158 and a guide 160. Withregard to FIG. 12, the first handle portion 154 can define a first ordistal end 162, a second or proximal end 164, a passage or throughbore166 and a cavity 168, The first handle portion 154 can also include oneor more indentations 154 a, which can facilitate the user grasping theinserter 12. Referring back to FIG. 11, the distal end 162 can include acollar 170, a ledge 172 and a slot 173. The collar 170 can besubstantially C-shaped. The collar 170 can include a plurality ofthreads 170 a and an opening 170 b. The plurality of threads 170 a cancouple the handle retaining portion 158 to the first handle portion 154.The opening 170 b can receive a portion of the second handle portion 156to couple the second handle portion 156 to the first handle portion 154.The ledge 172 can mate with the second handle portion 156 to assist incoupling the second handle portion 156 to the first handle portion 154.The slot 173 can be defined from the distal end 162 to an area adjacentto the proximal end 164. The slot 173 can receive the second handleportion 156 to couple the second handle portion 156 to the first handleportion 154.

With reference to FIGS. 11 and 12, the proximal end 164 of the firsthandle portion 154 can include a groove 174. The groove 174 can be sizedsuch that the lip 133 of the activation device 92 can be received overthe groove 174 to assist in coupling the activation device 92 to thefirst handle portion 154.

With continued reference to FIG. 12, the throughbore 166 can extend fromthe distal end 162 to the proximal end 164. The throughbore 166 can havea first portion 166 a defined adjacent to the distal end 162, from thedistal end 162 to the cavity 168, and a second portion 166 b, adjacentto the proximal end 164, from the proximal end 164 to the cavity 168.The first portion 166 a can be sized to receive the coupling portion152, a portion of the attachment system 66, a portion of the activeangle system 68 therethrough, and the guide 160. The second portion 166b can be sized to receive a portion of the attachment system 66therethrough, along with a portion of the driver 114.

The cavity 168 can be defined between the first portion 166 a and thesecond portion 166 b of the throughbore 166. The cavity 168 can be sizedto receive a portion of the driver 114 and the proximal end 96 of theactive arm 86 and the proximal end 106 of the passive arm 88. The cavity168 can cooperate with the shoulders 100, 110 of the active arm 86 andpassive arm 88 to limit the motion of the active arm 86 and passive arm88 relative to the housing 70. With reference to FIG. 13, the cavity 168can also include an annular recess 169, which can receive the annularprojection 126 of the pivoting link 116 to the first handle portion 154.The cavity 168 can movably or pivotably receive the annular projection126 of the pivoting link 116 to enable the pivoting link 116 to move orpivot relative to the first handle portion 154.

With regard to FIGS. 11 and 13, the second handle portion 156 can becoupled to the first handle portion 154 to enclose the cavity 168. Thesecond handle portion 156 can include a projection 176, a lip 178 (FIG.13) and an alignment device 179. The projection 176 can be receivedwithin the opening 170 b of the collar 170. The lip 178 can be formed atan end 156 a and can be received within a recess 181 defined in thefirst handle portion 154. The projection 176 and the lip 178 can assistin coupling the second handle portion 156 to the first handle portion154. The alignment device 179 can include an arm 183. The arm 183 canhave a projection 183 a, which can engage the groove 79 of the rod 72 toassist in aligning the rod 72. The arm 183 can be coupled to the secondhandle portion 156 via a mechanical fastener 185.

The handle retaining portion 158 can couple the distal portion 140 ofthe housing 70 to the proximal portion 142 of the housing 70. The handleretaining portion 158 can be generally annular, and can taper from afirst end 158 a to a second end 158 b. The handle retaining portion 158can include a bore 180. The bore 180 can include a first portion 180 aand a second portion 180 b. The first portion 180 a can have a diametersized to fit around the coupling portion 152 and a portion of theattachment system 66. The second portion 180 b can be sized to fit overthe flange 153 of the distal portion 140 and can include a plurality ofthreads. The plurality of threads can threadably engage the plurality ofthreads 170 a of the collar 170 to couple handle retaining portion 158to the proximal portion 142 of the housing 70. As the flange 153 of thedistal portion 140 can be received within the bore 180, the handleretaining portion 158 can couple the distal portion 140 of the housing70 to the proximal portion 142 of the housing 70. Similarly, with regardto FIG. 13, as the projection 176 of the second handle portion 156 canbe received within the opening 170 b of the collar 170, the handleretaining portion 158 can also couple the second handle portion 156 tothe first handle portion 154.

With reference to FIG. 11, the guide 160 can be received within thefirst portion 166 a of the throughbore 166. The guide 160 can assist indirecting the movement of the active arm 86, passive arm 88 and rod 72within the housing 70. The guide 160 can include a first arm slot 184, asecond arm slot 186 and a bore 188. The first arm slot 184 can begenerally opposite the second arm slot 186. The first arm slot 184 andthe second arm slot 186 can be substantially U-shaped to receive arespective one of the active arm 86 and the passive arm 88. The bore 188can be defined between the first arm slot 184 and the second arm slot186. The bore 188 can slidably receive the rod 72 therethrough.

In one exemplary method, with continued reference to FIG. 11, in orderto assemble the inserter 12, the driver 114 can be positioned within thefirst handle portion 154, so that the activation device 92 can becoupled to the driver 114. Then, with the guide 160 coupled to thehousing 70 along with the pivoting link 116, the active arm 86 can beinserted into the cavity 168 and through the throughbore 166. The activearm 86 can be placed into driving engagement with the driver 114. Then,the passive arm 88 can be positioned within the cavity 168 and directedthrough the throughbore 166. The rod 72 can be passed through the firsthandle portion 154 and the driver 114 so that the knob 74 can be coupledto the rod 72.

Next, the distal portion 140 of the housing 70 can be coupled to theproximal portion 142 so that the coupling portion 152 is received withinthe throughbore 166, and the rod 72 can pass through the cannulated bore150 of the distal portion 140. The active arm 86 and the passive arm 88can be positioned within a respective one of the first arm guide 146 andthe second arm guide 148. Then, the second handle portion 156 can becoupled to the first handle portion 154. The handle retaining portion158 can pass over the distal portion 140 until the handle retainingportion 158 is threadably engaged with the collar 170 to couple thedistal portion 140 to the proximal portion 142, and the second handleportion 156 to the first handle portion 154.

With the inserter 12 assembled, with reference to FIG. 12, the curvedspacer 10 can be coupled to the inserter 12. In order to couple thecurved spacer 10 to the inserter 12, the plurality of threads 80 a ofthe rod 72 can be threadably engaged with the plurality of threads 46 aof the coupling portion 16 by rotating the knob 74. In order to move orpivot the curved spacer 10 relative to the inserter 12. the activationdevice 92 can be rotated in a first direction. The rotation of theactivation device 92 can cause the rotation of the driver 114. Therotation of the driver 114 can cause the linear translation of theactive arm 86 in the first direction. The pivoting link 116 can transferthe linear translation of the active arm 86 to the passive arm 88, whichcan cause the passive arm 88 to move in an opposite, second direction(FIG. 14). The linear translation of the active arm 86 can cause thedistal end 94 of the active arm 86 to apply a force against the pocket42 of the curved spacer 10 to pivot the curved spacer 10. The reciprocalmovement of the passive arm 88 can move the distal end 104 of thepassive arm 88 rearward, towards the inserter 12, to enable the curvedspacer 10 to rotate. In one example, with reference to FIG. 15, thecurved spacer 10 can be positioned at an angle B, which can be about 25degrees relative to the inserter 12.

In another example, the activation device 92 can be rotated in a seconddirection. The rotation of the activation device 92 in the seconddirection can cause the active arm 86 to move in the second direction,and the passive arm 88 to move in an opposite, first direction. In oneexample, with reference to FIG. 16, the curved spacer 10 can bepositioned at an angle C, which can be about 80 degrees relative to theinserter 12.

Thus, the inserter 12 can be used to navigate the curved spacer 10through the anatomy. In one example, with a small incision formed nearthe intervertebral disc space and a window formed in a disc annulus, thecurved spacer 10 can be positioned at about 80 degrees relative to theinserter 12 (FIG. 16). The inserter 12 can guide the curved spacer 10through the window in the disc annulus, and then, the activation device92 can be rotated to place the curved spacer 10 at about 25 degreesrelative to the inserter 12 (FIG. 15). By allowing the curved spacer 10to be positioned at about 25 degrees relative to the inserter 12, thecurved spacer 10 can be placed along the curved anterior portion of thevertebral body V to restore disc height, while stabilizing the vertebralbody V for long-term spinal fusion (FIG. 2).

With reference now to FIGS. 17-21, in one example, an inserter 200 canbe employed with the curved spacer 10 to navigate the curved spacer 10through the anatomy. As the inserter 200 can be similar to the inserter12 described with reference to FIGS. 1-16, only the differences betweenthe inserter 12 and the inserter 200 will be discussed in great detailherein, and the same reference numerals will be used to denote the sameor similar components. The inserter 200 can be composed of anybiocompatible material, such as a biocompatible metal or polymer. In oneexample, the inserter 200 can comprise a variable angle inserter, whichcan enable a user to position the curved spacer 10 at a selected anglefor the insertion of the curved spacer 10 into the anatomy, as will bediscussed. The inserter 200 can comprise an attachment system 202 and ahousing 206.

With reference to FIG. 18, the attachment system 202 can couple thecurved spacer 10 to the inserter 200. The attachment system 202 caninclude a rod 208 and a knob 210. The rod 208 can include the first ordistal end 76 and a second or proximal end 212. The proximal end 212 caninclude a plurality of threads 214, a first collar 216, a second collar218 and a third collar 220. The plurality of threads 214 can serve as astop for the movement of the rod 208 within the housing 206. The firstcollar 216 can have a plurality of projections 216 a. The second collar218 can be cylindrical and substantially smooth. The second collar 218can be formed between the first collar 216 and the third collar 220. Thethird collar 220 can be located at a proximalmost end 212 a of the rod208. The third collar 220 can include an elongated slot 222, which canbe defined in a direction substantially perpendicular to a longitudinalaxis of the rod 208. The elongated slot 222 can receive a pin 224, whichcan couple the knob 210 to the rod 208 (FIG. 20). The elongated slot 222can enable the pin 224 to move along the elongated slot 222 to absorbforces during impaction of the knob 210.

With regard to FIG. 18, the knob 210 can enable the user to rotate therod 208 to couple or uncouple the curved spacer 10 from the inserter200. The knob 210 can include a counterbore 226, a pin bore 228, abiasing member or spring 230 and the graspable portion 84. Withreference to FIG. 20, the counterbore 226 can receive the proximalmostend 212 a of the rod 208. With reference now to FIG. 21, the pin bore228 can receive the pin 224 therethrough to couple the rod 208 to theknob 210. The spring 230 can be retained within the counterbore 226,rearward or proximal of the pin bore 228 (e.g., away from the distal endof the rod 208). The spring 230 can prevent the knob 210 from rattlingaround when the instrument is manipulated. The knob 210 can translaterelative to the rod 208 against a bias of the spring 230, In thismanner, impact forces delivered to the knob 210 are shielding from therod 208 and thus the implant. Impact forces are redirected to thesupport shaft 246.

Generally, the knob 210 can be rotated in one direction to thread thethreaded portion 80 into engagement with the coupling portion 16 of thecurved spacer 10 to couple the curved spacer 10 to the inserter 200. Inorder to disengage the curved spacer 10 from the inserter 200, the knob210 can be rotated in an opposite direction to remove the threadedportion 80 from the coupling portion 16 to disengage the curved spacer10 from the inserter 200.

With regard to FIG. 18, the housing 206 can enclose at least a portionof the attachment system 202. The housing 206 can also provide agraspable portion for the user. The housing 206 can include a first ordistal portion 232 and a second or proximal portion 234. The distalportion 232 of the housing 206 can be elongated. As best illustrated inFIG. 17, the distalmost end 232 a of the distal portion 232 can includea first curved surface 236 a opposite a second curved surface 236 b. Thefirst curved surface 236 a and the second curved surface 236 b cancorrespond to a shape of the proximal end 20 of the curved spacer 10 andcan include a plurality of teeth 236 c. The plurality of teeth 236 c canfrictionally engage the proximal end 20 of the curved spacer 10 toassist in fixedly coupling the curved spacer 10 to the inserter 200.With reference to FIG. 18, the distal portion 232 can also include acoupling portion 238. The coupling portion 238 can comprise a pluralityof threads 238 a. The plurality of threads 238 a can be used to couplethe distal portion 232 to the proximal portion 234.

The proximal portion 234 can enclose a portion of the attachment system202. The proximal portion 234 can include a retaining portion 240, agraspable portion 242, a first support shaft 244 and a second supportshaft 246. The retaining portion 240 can assist in coupling the distalportion 232 to the proximal portion 234. The retaining portion 240 canbe annular. The retaining portion 240 can include a bore 248 and a lip250. With reference to FIG. 20, the bore 248 can be defined through theretaining portion 240 and can enable a portion of the distal portion 232to pass through the retaining portion 240. The lip 250 can be sized sothat the retaining portion 240 can be press or snap-fit onto a first end252 of the graspable portion 242.

The graspable portion 242 can include the first end 252, a second end254, one or more indentations 256 and a throughbore 258. The second end254 can be opposite the first end 252. The indentations 256 can providea graspable surface for the user. The throughbore 258 can be definedthrough the graspable portion 242 from the first end 252 to the secondend 254. The throughbore 258 can receive the first support shaft 244 andthe second support shaft 246.

The first support shaft 244 can be wholly received within thethroughbore 258. The first support shaft 244 can include a first end260, a second end 262 and a throughbore 264. The first end 260 can bepositioned adjacent the first end 252 of the graspable portion 242 whenthe first support shaft 244 is coupled to the graspable portion 242. Thesecond end 262 can be positioned adjacent to a portion of the secondsupport shaft 246. With regard to FIG. 20, the throughbore 264 can havea first portion 264 a at the first end 260, and a second portion 264 b,which can extend from an area adjacent to the first end 260 to an areaadjacent to the second end 262. The throughbore 264 can also include athird portion 264 c at the second end 262. The first portion 264 a canbe rectangular in shape to receive a portion of the distal portion 232of the housing 206 (FIG. 18). The second portion 264 b can be circularin shape, and can receive a portion of the second support shaft 246. Thethird portion 264 c can be circular in shape and can have a diametergreater than a diameter of the second portion 264 b. The third portion264 c can assist in coupling the second support shaft 246 to thegraspable portion 242.

The second support shaft 246 can be partially received within the firstsupport shaft 244. Referring to FIG. 18, the second support shaft 246can include a distal portion 270, a proximal portion 272 and a bore 274.The distal portion 270 can be received within the first support shaft244. The distal portion 270 can be substantially cylindrical in shape,and can have a diameter, which can be smaller than a diameter of theproximal portion 272.

The proximal portion 272 can include a first collar 276 and a secondcollar 278. The first collar 276 can be received within the thirdportion 264 c of the throughbore 264. With regard to FIG. 21, the secondcollar 278 can include a first coupling bore 280, a second coupling bore282 and a groove 284. The first coupling bore 280 and the secondcoupling bore 282 can be defined in a direction substantiallyperpendicular to the bore 274. Each of the first coupling bore 280 andthe second coupling bore 282 can extend to the bore 274 and can includea plurality of threads 280 a, 282 a. The plurality of threads 280 a, 282a can each threadably receive a mechanical fastener 285. The groove 284can provide a graspable surface.

Referring to FIGS. 20 and 21, the bore 274 can be sized to receive aportion of the housing 206 and the attachment system 202 therethrough.The bore 274 can include a plurality of threads 286 at a distalmost end270 a of the distal portion 270. The plurality of threads 286 canthreadably engage the coupling portion 238 of the distal portion 232 ofthe housing 206. The bore 274 can include a plurality of threads 288 atthe proximal portion 272. The plurality of threads 288 can cooperatewith the plurality of threads 214 of the rod 208 to limit the motion ofthe rod 208 within the housing 206.

In one exemplary method, with regard to FIG. 18, in order to assemblethe inserter 200, the rod 208 can be inserted through the second supportshaft 246. The second support shaft 246 can be inserted into the firstsupport shaft 244, and then the first support shaft 244 can be insertedinto the graspable portion 242. The mechanical fasteners 285 can then beinserted into the coupling bores 280, 282 (FIG. 21).

With the retaining portion 240 disposed over the distal portion 232 ofthe housing 206, the distal portion 232 can be positioned into thegraspable portion 242 and threadably engaged with the second supportshaft 246. The retaining portion 240 can then be snapped into the firstend 252 of the graspable portion 242. With the spring 230 positionedwithin the counterbore 226 of the knob 210, the knob 210 can bepositioned about the third collar 220 of the rod 208. The pin 224 can beinserted into the pin bore 228 and through the elongated slot 222 tocouple the knob 210 to the rod 208.

With the inserter 200 assembled, the curved spacer 10 can be coupled tothe inserter 200 at a desired angle. In one example, similar to theinserter 12, the curved spacer 10 can be coupled to the inserter 200 atabout a 25 degree angle. In order to couple the curved spacer 10 to theinserter 12, the plurality of threads 80 a of the rod 208 can bethreadably engaged with the plurality of threads 46 a of the couplingportion 16 by rotating the knob 210. With the curved spacer 10 coupledto the inserter 200, the inserter 200 can be used to navigate the curvedspacer 10 through the anatomy, as discussed with regard to the inserter12, above. In another example, the curved spacer 10 can be coupled tothe inserter 200 at about an 80 degree angle. In order to couple thecurved spacer 10 to the inserter 12, the plurality of threads 80 a ofthe rod 208 can be threadably engaged with the plurality of threads 46 aof the coupling portion 16 by rotating the knob 210.

With reference now to FIGS. 22-26, in one example, an inserter 300 canbe employed with the curved spacer 10 to navigate the curved spacer 10through the anatomy. As the inserter 300 can be similar to the inserter200 described with reference to FIGS. 17-21, only the differencesbetween the inserter 200 and the inserter 300 will be discussed in greatdetail herein, and the same reference numerals will be used to denotethe same or similar components. The inserter 300 can be composed of anybiocompatible material, such as a biocompatible metal or polymer. In oneexample, the inserter 300 can comprise a fixed angle inserter, which canenable a user to position the curved spacer 10 at a fixed angle for theinsertion of the curved spacer 10 into the anatomy, as will bediscussed. The inserter 300 can comprise an attachment system 302 and ahousing 306.

The attachment system 302 can couple the curved spacer 10 to theinserter 300. With reference to FIG. 23, the attachment system 302 caninclude a rod 308 and the knob 210. The rod 308 can include the first ordistal end 76 and a second or proximal end 312. The proximal end 312 caninclude a plurality of threads 314, a first raised portion 316 and thethird collar 220. The plurality of threads 314 can serve as a stop forthe movement of the rod 308 within the housing 306. The plurality ofthreads 314 can be formed on the first raised portion 316. The firstraised portion 316 can also define a tapered portion 316 a. The taperedportion 316 a can contact a portion of the housing 306 to limit themotion of the rod 308 within the housing 306.

The housing 306 can enclose at least a portion of the attachment system302. The housing 306 can also provide a graspable portion for the user.The housing 306 can include a first or distal portion 332 and a secondor proximal portion 334. The distal portion 332 of the housing 306 canbe elongated. As best illustrated in FIG. 22, the distalmost end 332 aof the distal portion 332 can include a first curved surface 336 aopposite a second curved surface 336 b. The distal portion 332 can alsoinclude coupling portion 238. The first curved surface 336 a can beopposite the second curved surface 336 b. The first curved surface 336 aand the second curved surface 336 b can correspond to a shape of theproximal end 20 of the curved spacer 10. Each of the first curvedsurface 336 a and the second curved surface 336 b can include ananti-rotation nub 338 a, 338 b.

The anti-rotation nub 338 a, 338 b can protrude from the first curvedsurface 336 a and the second curved surface 336 b and can engage themain body 14 of the curved spacer 10. The engagement between theanti-rotation nub 338 a, 338 b and the main body 14 can prevent the mainbody 14 from moving or rotating relative to the inserter 300. In oneexample, the anti-rotation nub 338 a can extend a greater distance thanthe anti-rotation nub 338 b to enable the inserter 300 to be attached atone of two preferred angles. In this regard, in one example withreference to FIG. 27, if the curved spacer 10 is coupled to the inserter300 in a first orientation, the curved spacer 10 can be orientated at anangle FA of about 70 degrees relative to the inserter 300. If theinserter 300 is rotated about 180 degrees relative to the curved spacer10, then with reference to FIG. 28, the curved spacer 10 can beorientated at an angle FB of about 45 degrees relative to the inserter300. It should be noted that these preferred angles are merelyexemplary, as the anti-rotation nub 338 a, 338 b could be configured sothat the curved spacer 10 could be coupled at any desired angle relativeto the inserter 300. As a further example, the anti-rotation nubs 338 a,338 b can be formed so that the curved spacer 10 remains in the sameorientation regardless of how the curved spacer 10 is coupled to theinserter 300.

Referring to FIG. 23, the proximal portion 334 can enclose a portion ofthe attachment system 302. The proximal portion 334 can include theretaining portion 240, the graspable portion 242, the first supportshaft 244 and a second support shaft 346. The second support shaft 346can be partially received within the first support shaft 244. The secondsupport shaft 346 can include the distal portion 270, a proximal portion372 and the bore 274. The tapered portion 316 a of the first raisedportion 316 of the rod 308 can contact the distal portion 270 to preventthe further advancement of the rod 308. The proximal portion 372 caninclude the first collar 276 and a second collar 378. The second collar378 can include the groove 284.

In one exemplary method, in order to assemble the inserter 300, the rod308 can be inserted through the second support shaft 346. The secondsupport shaft 346 can be inserted into the first support shaft 244, andthen the first support shaft 244 can be inserted into the graspableportion 242. With the retaining portion 240 disposed over the distalportion 232 of the housing 206, the distal portion 232 can be positionedinto the graspable portion 242 and threadably engaged with the secondsupport shaft 346. The retaining portion 240 can then be snapped intothe first end 252 of the graspable portion 242. With the spring 230positioned within the counterbore 226 of the knob 210, the knob 210 canbe positioned about the third collar 220 of the rod 308. The pin 224 canbe inserted into the pin bore 228 and through the elongated slot 222 tocouple the knob 210 to the rod 308.

With the inserter 300 assembled, the curved spacer 10 can be coupled tothe inserter 300 at the angle defined by the anti-rotation nubs 338 a,338 b. In one example, the curved spacer 10 can be coupled to theinserter 300 at about a 70 degree angle (FIG. 27). In order to couplethe curved spacer 10 to the inserter 12, the plurality of threads 80 aof the rod 308 can be threadably engaged with the plurality of threads46 a of the coupling portion 16 by rotating the knob 210. With thecurved spacer 10 coupled to the inserter 300, the inserter 300 can beused to navigate the curved spacer 10 through the anatomy, as discussedwith regard to the inserter 12, above.

With reference now to FIGS. 29-34, in one example, an inserter 400 canbe employed with the curved spacer 10 to navigate the curved spacer 10through the anatomy. As the inserter 400 can be similar to the inserter200 described with reference to FIGS. 17-21, only the differencesbetween the inserter 200 and the inserter 400 will be discussed in greatdetail herein, and the same reference numerals will be used to denotethe same or similar components. The inserter 400 can be composed of anybiocompatible material, such as a biocompatible metal or polymer. In oneexample, the inserter 400 can comprise a variable angle inserter, whichcan enable a user to lock the curved spacer 10 at a selected angle forthe insertion of the curved spacer 10 into the anatomy, as will bediscussed. The inserter 400 can comprise an attachment system 402 and ahousing 406.

The attachment system 402 can couple the curved spacer 10 to theinserter 400. With reference to FIG. 30, the attachment system 402 caninclude a rod 408 and a knob 410. The rod 408 can include the first ordistal end 76 and a second or proximal end 412. The proximal end 412 caninclude the plurality of threads 214 and a third collar 420. The thirdcollar 420 can be located at a proximalmost end 412 a of the rod 408.The third collar 420 can be elongated, and can include an elongated slot422, which can be defined in a direction substantially perpendicular toa longitudinal axis of the rod 408. The elongated slot 422 can receivethe pin 224, which can couple the knob 410 to the rod 408. The elongatedslot 422 can enable the pin 224 to move along the elongated slot 422 toabsorb forces during impaction of the knob 410.

The knob 410 can enable the user to rotate the rod 408 to couple oruncouple the curved spacer 10 from the inserter 400. With reference toFIGS. 30 and 32, the knob 410 can include a counterbore 426, a pin bore428 and a graspable portion 430. The counterbore 426 can receive theproximalmost end 412 a of the rod 408. The pin bore 428 can receive thepin 224 therethrough to couple the rod 408 to the knob 410. Thegraspable portion 430 can provide a surface for the user to manipulatethe knob 410.

Generally, the knob 410 can be rotated in one direction to thread thethreaded portion 80 of the rod 408 into engagement with the couplingportion 16 of the curved spacer 10 to couple the curved spacer 10 to theinserter 400. In order to disengage the curved spacer 10 from theinserter 400, the knob 410 can be rotated in an opposite direction toremove the threaded portion 80 from the coupling portion 16 to disengagethe curved spacer 10 from the inserter 400.

The housing 406 can enclose at least a portion of the attachment system402. With reference to FIG. 30, the housing 406 can also provide agraspable portion for the user. The housing 406 can include a first ordistal portion 432 and a second or proximal portion 434. The distalportion 432 of the housing 406 can comprise an elongated body. Thedistalmost end 432 a of the distal portion 432 can include the firstcurved surface 236 a opposite the second curved surface 236 b. Thedistal portion 432 can also include a coupling portion 438 and a flange440. The coupling portion 438 can have a diameter sized to enable thecoupling portion 438 to be press fit onto the proximal portion 434. Thecoupling portion 438 can be substantially cylindrical. The flange 440can be annular, and can be formed about a circumference of the couplingportion 438. The flange 440 can engage a portion of the proximal portion434 to assist in coupling the distal portion 432 to the proximal portion434.

The proximal portion 434 can enclose a portion of the attachment system402. The proximal portion 434 can include a graspable portion 442 and alocking portion 444. The graspable portion 442 can include a first end452, a second end 454, the one or more indentations 256 and athroughbore 456. The first end 452 can include a substantiallycylindrical projection 458. The cylindrical projection 458 can be sizedto enable the coupling portion 438 to be press-fit therein. The flange440 of the distal portion 432 can be engaged with a distalmost end 458 aof the cylindrical projection 458 to assist in coupling the distalportion 432 to the proximal portion 434. The second end 454 can beopposite the first end 452.

With reference to FIG. 32, the second end 454 can be coupled to thelocking portion 444. The second end 454 can include a cylindricalprotrusion 460. The cylindrical protrusion 460 can extend outwardly fromthe second end 454. The cylindrical protrusion 460 can have a diameterless than a diameter of the graspable portion 442. The cylindricalprotrusion 460 can include a bore 460 a. The bore 460 a can receive apin 462, which can couple the locking portion 444 to the graspableportion 442. The throughbore 456 can be defined through the graspableportion 442 from the first end 452 to the second end 454. Thethroughbore 456 can be sized to enable the rod 408 to pass through thegraspable portion 442.

With regard to FIG. 30, the locking portion 444 can be substantiallycylindrical. The locking portion 444 can include a first end 464, asecond end 466, a central bore 468 and a locking tab 470. Referring toFIG. 32, the first end 464 can be coupled to the cylindrical protrusion460 and positioned adjacent to the second end 454 of the graspableportion 442. The first end 464 can include an aperture 472. The aperture472 can be defined in a direction substantially perpendicular to thecentral bore 468. The aperture 472 can receive the pin 462 therethroughto couple the locking portion 444 to the graspable portion 442.

The second end 466 can be adjacent to the knob 410 when the attachmentsystem 402 is coupled to the housing 406. The second end 466 can includea locking slot 474. The locking slot 474 can be defined through thelocking portion 444. The locking slot 474 can be defined so as to besubstantially perpendicular to the central bore 468. The locking slot474 can receive the locking tab 470.

The central bore 468 can pass through the first end 464 to the secondend 466. The central bore 468 can enable the rod 408 to pass through thelocking portion 444. At the first end 464, the central bore 468 can alsobe sized to receive the cylindrical protrusion 460. At the second end466, the central bore 468 can be sized to receive the third collar 420.

With regard to FIG. 33, the locking tab 470 can be received within thelocking slot 474. The locking tab 470 can include a first surface 478, asecond surface 480 and a bore 482. The first surface 478 can include aspring 484. The spring 484 can bias against a portion of the lockingslot 474 to apply tension to the rod 408. The second surface 480 can beopposite the first surface 478. The second surface 480 can define a ramp480 a. The ramp 480 a can be formed about a portion of the bore 482. Theramp 480 a can cooperate with the spring 484 to apply tension to the rod408. The application of tension to the rod 408 can further couple thecurved spacer 10 to the inserter 400. The bore 482 can be elongated toenable the locking tab 470 to move relative to the rod 408 within thelocking slot 474.

In one exemplary method, with reference to FIG. 30, in order to assemblethe inserter 400, the distal portion 432 can be coupled to the graspableportion 442 of the housing 406. Then, the locking portion 444 can becoupled to the graspable portion 442 of the housing 406 by inserting thepin 462 through the aperture 472. The locking tab 470 can be positionedwithin the locking slot 474 so that the bore 482 is substantiallycoaxially aligned with the throughbore 456 of the graspable portion 442.Next, the rod 408 can be inserted through the housing 406. The knob 410can be positioned over the third collar 220 of the rod 408 and the pin224 can be inserted through the pin bore 428 and the elongated slot 222to couple the knob 410 to the rod 408.

With the inserter 400 assembled, the curved spacer 10 can be coupled tothe inserter 400 at a desired angle. In one example, with reference toFIG. 34, the curved spacer 10 can be coupled to the inserter 400 at anangle VA of about a 80 degree angle. In order to couple the curvedspacer 10 to the inserter 400, the plurality of threads 80 a of the rod408 can be threadably engaged with the plurality of threads 46 a of thecoupling portion 16 by rotating the knob 410. Then, the locking tab 470can be advanced through the locking slot 474 to apply tension to the rod408. The application of tension to the rod 408 can fixedly couple orlock the curved spacer 10 to the inserter 400. With the curved spacer 10fixedly coupled to the inserter 400, the inserter 400 can be used tonavigate the curved spacer 10 through the anatomy, as discussed withregard to the inserter 12, above.

In use, if it is desired to change the angle of the curved spacer 10relative to the inserter 400, the locking tab 470 can be moved in thelocking slot 474 to release the tension on the rod 408. Then, the curvedspacer 10 can be moved to another selected angle, such as about a 25degree angle, for example. Then, the locking tab 470 can be advancedthrough the locking slot 474 to apply tension to the rod 408 to fixedlycouple lock the curved spacer 10 to the inserter 400.

With reference now to FIGS. 35-39, in one example, an inserter 500 canbe employed with the curved spacer 10 to navigate the curved spacer 10through the anatomy. As the inserter 500 can be similar to the inserter400 described with reference to FIGS. 29-34, only the differences 400and the inserter 500 will be discussed in great detail herein, and thesame reference numerals will be used to denote the same or similarcomponents. The inserter 500 can be composed of any biocompatiblematerial, such as a biocompatible metal or polymer. In one example, theinserter 500 can comprise a variable angle inserter, which can enable auser to lock the curved spacer 10 at a selected angle for the insertionof the curved spacer 10 into the anatomy, as will be discussed. Theinserter 500 can comprise an attachment system 502 and a housing 506.

With reference to FIG. 36, the attachment system 502 can couple thecurved spacer 10 to the inserter 500. The attachment system 502 caninclude the rod 408 and a knob 510. The knob 510 can enable the user torotate the rod 408 to couple or uncouple the curved spacer 10 from theinserter 500. The knob 510 can include the counterbore 426, the pin bore428 and a graspable portion 530. The graspable portion 530 can provide asurface for the user to manipulate the knob 510.

The housing 506 can enclose at least a portion of the attachment system502. The housing 506 can also provide a graspable portion for the user.The housing 506 can include the first or distal portion 432 and a secondor proximal portion 534. The proximal portion 534 can enclose a portionof the attachment system 502. The proximal portion 534 can include acoupling portion 540, a graspable portion 542, a base 544 and a lockingportion 546. The coupling portion 540 can include an annular portion548, a projection 550 and a bore 552. The annular portion 548 can have adiameter sized to mate with a first end 554 of the graspable portion542.

The projection 550 can extend outwardly from the annular portion 548 andcan have a diameter smaller than a diameter of the annular portion 548to enable the projection 550 to be received within the graspable portion542. The projection 550 can have a plurality of threads 550 a, which canthreadably engage a portion of the graspable portion 542 to couple thecoupling portion 540 to the graspable portion 542 (FIG. 38). Withreference to FIGS. 36 and 38, the bore 552 can extend through thecoupling portion 540 from the annular portion 548 through the projection550. In one example, the bore 552 can include a plurality of threads 552a, which can enable the coupling portion 438 of the distal portion 432to be press-fit into the coupling portion 540. It should be noted thebore 552 could also be smooth.

The graspable portion 542 can include a first end 554, a second end 556,the one or more indentations 256 and a throughbore 560. The first end554 can be adjacent to the coupling portion 540 when the couplingportion 540 is coupled to the graspable portion 542. The second end 556can be adjacent to the base 544 when the base 544 is coupled to thegraspable portion 542. With reference to FIG. 38, the throughbore 560can extend through the graspable portion 542 from the first end 554 tothe second end 556. The throughbore 560 can include a first plurality ofthreads 560 a at the first end 554 and a second plurality of threads 560b at the second end 556. The first plurality of threads 560 a can have adiameter sized to threadably engage the plurality of threads 550 a ofthe projection 550 to couple the coupling portion 540 to the graspableportion 542. The second plurality of threads 560 b can have a diametersized to threadably engage a portion of the base 544 to couple the base544 to the graspable portion 542. The throughbore 560 can also be sizedto enable the rod 408 to pass through the graspable portion 542.

Referring to FIGS. 36 and 38, the base 544 can include a projection 562and an annular portion 564. The projection 562 can extend from theannular portion 564 and can be sized to be received within thethroughbore 560 of the graspable portion 542 at the second end 556. Theprojection 562 can include a plurality of threads 562 a, which canthreadably engage the second plurality of threads 560 b of thethroughbore 560 to couple the base 544 to the graspable portion 542. Theannular portion 564 can be sized to mate with the second end 556 of thegraspable portion 542, and can include a plurality of threads 562 adisposed about a periphery or circumference of the annular portion 564.The plurality of threads 562 a can couple the locking portion 546 to thebase 544.

The locking portion 546 can include a substantially cylindrical housing566 and a locking tab 568. The housing 566 can have a first or distalend 570, a second or proximal end 572, a cavity 574 and a slot 576. Withreference to FIG. 38, the distal end 570 can be configured to bepositioned over the annular portion 564 of the base 544 and can includea plurality of threads 570 a. The plurality of threads 570 a canthreadably engage the plurality of threads 562 a of the annular portion564 to threadably couple the housing 566 to the base 544.

With continuing reference to FIG. 38, the second or proximal end 572 caninclude a bore 572 a, which can be sized to enable the third collar 220of the rod 408 to pass through the housing 566. The cavity 574 can besized to receive the locking tab 568 so that the locking tab 568 canmove or rotate within the cavity 574. The slot 576 can enable a portionof the locking tab 568 to extend beyond the housing 566 to enable a userto manipulate the locking tab 568.

The locking tab 568 can include a cylindrical housing 578 and a tab 580.The cylindrical housing 578 can be received within the cavity 574 suchthat a longitudinal axis of the cylindrical housing 578 is substantiallyperpendicular to a longitudinal axis of the inserter 500. As bestillustrated in FIG. 39, the cylindrical housing 578 can include a firstslot 582, a second slot 584, a first biasing member 586 and a secondbiasing member 588. The first slot 582 and the second slot 584 can bediametrically opposed from each other within the cylindrical housing578. The rod 408 can be received through a portion of the first slot 582and the second slot 584. The first slot 582 and the second slot 584 canbe substantially triangular to define a range of movement for the tab580 about the rod 408, as will be discussed.

The first biasing member 586 and the second biasing member 588 can eachbe defined along a perimeter 582 a, 584 a of a respective one of thefirst slot 582 and second slot 584. The first biasing member 586 and thesecond biasing member 588 can each include a slot 586 a, 588 a, whichcan enable the first biasing member 586 and the second biasing member588 to move about the rod 408. The first biasing member 586 and thesecond biasing member 588 can act as a living spring to apply tension tothe rod 408. In this regard, when the first biasing member 586 and thesecond biasing member 588 are moved from a first position to a secondposition, an end 586 b, 588 b of each of the first biasing member 586and the second biasing member 588 can bias against a respective one ofthe base 544 and the housing 566 to apply tension to the third collar220 of the rod 408. This can assist in fixedly coupling the curvedspacer 10 to the inserter 500.

The tab 580 can be used to move the first biasing member 586 and thesecond biasing member 588 between the first position and the secondposition. In one example, in the first position, the tab 580 can beadjacent to a first edge 576 a of the slot 576, and in the secondposition, the tab 580 can be adjacent to a second end 576 b of the slot576. The tab 580 can extend outwardly from the housing 566 and can beintegrally formed with the cylindrical housing 578 of the locking tab568. It should be noted that the tab 580 could be discretely formed andcoupled to the locking tab 568 in a post processing step, for example.

In one exemplary method, with reference to FIG. 36, in order to assemblethe inserter 500, the coupling portion 540 can be coupled to the firstend 554 of the graspable portion 542, and the base 544 can be coupled tothe second end 556 of the graspable portion 542. Then, the distalportion 432 can be coupled to the graspable portion 442 of the housing406. With the locking tab 568 positioned within the housing 566, thehousing 566 of the locking portion 546 can be coupled to the base 544.Next, the rod 408 can be inserted through the housing 506. The knob 510can be positioned over the third collar 220 of the rod 408 and the pin224 can be inserted through the pin bore 428 and the elongated slot 222to couple the knob 510 to the rod 408.

With the inserter 500 assembled, the curved spacer 10 can be coupled tothe inserter 500 at a desired angle. In one example, the curved spacer10 can be coupled to the inserter 500 at about a 80 degree angle. Asdiscussed with regard to the inserter 400, in order to couple the curvedspacer 10 to the inserter 500, the plurality of threads 80 a of the rod408 can be threadably engaged with the plurality of threads 46 a of thecoupling portion 16 by rotating the knob 510. Then, the tab 580 of thelocking tab 568 can be moved from the first position to the secondposition to apply tension to the rod 408. The application of tension tothe rod 408 can fixedly couple or lock the curved spacer 10 to theinserter 500. With the curved spacer 10 fixedly coupled to the inserter500, the inserter 500 can be used to navigate the curved spacer 10through the anatomy, as discussed with regard to the inserter 12, above.

In use, if it is desired to change the angle of the curved spacer 10relative to the inserter 500, the tab 576 of the locking tab 568 can bemoved from the second position to the first position to release thetension on the rod 408. Then, the curved spacer 10 can be moved toanother selected angle, such as about a 25 degree angle, for example.Then, the tab 576 of the locking tab 568 can be moved from the firstposition to the second position to fixedly couple or lock the curvedspacer 10 to the inserter 500.

Accordingly, the curved spacer 10 can be coupled to any of the inserters12, 200, 300, 400, 500 and navigated through the anatomy into theintervertebral disc space. The inserter 12 can enable the user toactively select the angle for the curved spacer 10 relative to theinserter 12, which can allow the user to fully control the angle of thecurved spacer 10 throughout the entire implantation process. Theinserter 200 can allow the user to couple the curved spacer 10 to theinserter 200 at a desired angle, while the inserter 300 can enable theuser to couple the curved spacer 10 to the inserter 300 at a fixedangle. The inserters 400, 500 can allow the user to couple the curvedspacer 10 to the inserter 400, 500 at a desired angle, and the curvedspacer 10 can then be positioned within the anatomy. Once positionedwithin the anatomy, the locking tab 470, 568 can be unlocked to enablethe inserter 400, 500 to move relative to the curved spacer 10. Thelocking tab 470, 568 can then be locked, and the curved spacer 10further positioned within the anatomy. It should be noted that theinserters 12, 200, 300, 400, 500 can be provided individually, or couldbe each packaged with the curved spacer 10. Alternatively, the inserters12, 200, 300, 400, 500 could be packaged together with the curved spacer10 as a kit.

While specific examples have been described in the specification andillustrated in the drawings, it will be understood by those of ordinaryskill in the art that various changes can be made and equivalents can besubstituted for elements thereof without departing from the scope of thepresent teachings. Furthermore, the mixing and matching of features,elements and/or functions between various examples is expresslycontemplated herein so that one of ordinary skill in the art wouldappreciate from the present teachings that features, elements and/orfunctions of one example can be incorporated into another example asappropriate, unless described otherwise, above. Moreover, manymodifications can be made to adapt a particular situation or material tothe present teachings without departing from the essential scopethereof, Therefore, it is intended that the present teachings not belimited to the particular examples illustrated by the drawings anddescribed in the specification, but that the scope of the presentteachings will include any embodiments falling within the foregoingdescription.

What is claimed is:
 1. An instrument for inserting an intervertebral spacer, the instrument comprising: an elongated body comprising a proximal end, a distal end and a first passage extending from the proximal end to the distal end, the distal end including a first curved surface opposite a second curved surface and a circular bore disposed between, wherein the first curved surface and the second curved surface together correspond to a shape of a proximal end of the intervertebral spacer; a handle coupled to the proximal end of the elongated body, the handle comprising a proximal end, a distal end, and a second passage extending from the proximal end to the distal end; and an attachment system receivable through the first passage and the second passage including a distal end extending from the circular bore to couple the intervertebral spacer to the instrument for insertion, wherein the attachment system includes a rod receivable through the first passage and the second passage, the rod movable relative to the elongated body and the handle, the rod having a rod distal end that is removably coupleable to the intervertebral spacer, wherein the attachment system further includes a knob couplable to a proximal end of the rod, the knob operable to rotate the rod to couple and uncouple the intervertebral spacer, and wherein the attachment system further includes a spring disposed between a proximal end of the rod and a counterbore within the knob.
 2. The instrument of claim 1, further comprising a locking tab disposed within a locking slot in the handle, the locking tab including a locking spring positioned to bias against a portion of the locking slot to apply tension to the rod, wherein the tension on the rod biases the intervertebral spacer against the first curved surface and the second curved surface.
 3. The instrument of claim 2, wherein the locking tab is positionable between a first position to apply the tension against the rod, and a second position to release the tension against the rod, wherein with the locking tab positioned in the second position the intervertebral spacer can be articulated to a different angle with respect to the elongate body.
 4. The instrument of claim 1, wherein the first curved surface and the second curved surface include a plurality of teeth disposed therein for engaging the intervertebral spacer.
 5. The instrument of claim 1, wherein the first curved surface and the second curved surface each include an anti-rotation nub extending distally from an outer portion, the anti-rotation nub restricts movement of the intervertebral spacer relative to the elongate body.
 6. The instrument of claim 5, wherein the first curved surface extends a greater distance than the second curved surface.
 7. An instrument for inserting an intervertebral spacer, the instrument comprising: an elongated body comprising a proximal end, a distal end and a first passage extending from the proximal end to the distal end, the distal end including a first curved surface opposite a second curved surface and a circular bore disposed between, wherein the first curved surface and the second curved surface together correspond to a shape of a proximal end of the intervertebral spacer; a handle coupled to the proximal end of the elongated body, the handle comprising a proximal end, a distal end, and a second passage extending from the proximal end to the distal end; a rod receivable through the first passage and the second passage, the rod movable relative to the elongated body and the handle, the rod having a distal end that is removably coupleable to the intervertebral spacer; and a locking mechanism disposed adjacent the handle, the locking mechanism adapted to tension the rod in a proximal direction in a first position and release tension on the rod in a second position, wherein the locking tab further includes a cylindrical body including a first biasing member and a second biasing member configured to operate as a living spring to apply tension to the rod.
 8. The instrument of claim 7, wherein the locking mechanism includes a knob rotatably operable to transition between the first position and the second position.
 9. The instrument of claim 8, wherein the rod includes a rod threaded distal end to engage the intervertebral spacer, and wherein rotating the knob between the first position and the second position loosens the threaded connection with the intervertebral spacer.
 10. The instrument of claim 7, wherein the locking mechanism includes the locking tab disposed within a locking slot in the handle, the locking tab including the living spring positioned to bias against a portion of the locking slot to apply tension to the rod, wherein the tension on the rod biases the intervertebral spacer against the first curved surface and the second curved surface.
 11. The instrument of claim 10, wherein the locking tab shifts linearly within the locking slot transitioning from the first position to the second position.
 12. The instrument of claim 7, wherein the locking mechanism includes a cylindrical housing disposed adjacent the handle and the locking tab.
 13. The instrument of claim 12, wherein the cylindrical housing includes a first longitudinal axis oriented perpendicular to a second longitudinal axis of the instrument.
 14. The instrument of claim 12, wherein a portion of the locking tab extends outside the cylindrical housing through a slot to enable manipulation of the locking tab between the first position and the second position.
 15. The instrument of claim 7, wherein the locking tab operates to shift the first biasing member and the second biasing member between the first position and the second position.
 16. An instrument for inserting an intervertebral spacer, the instrument comprising: an elongated body comprising a proximal end, a distal end and a first passage extending from the proximal end to the distal end, the distal end including a curved surface and a circular bore disposed with the curved surface, wherein the curved surface corresponds to a shape of a proximal end of the intervertebral spacer; a handle coupled to the proximal end of the elongated body, the handle comprising a proximal end, a distal end, and a second passage extending from the proximal end to the distal end; an attachment system receivable through the first passage and the second passage including a distal end extending from the circular bore to couple the intervertebral spacer to the instrument for insertion; and a locking mechanism to lock the proximal end of the intervertebral spacer against the curved surface when the locking mechanism is in a first position, and to release the proximal end of the intervertebral spacer from the curved surface in a second position, wherein in the second position the intervertebral spacer remains coupled to a portion of the attachment system, and wherein the locking mechanism includes a locking tab disposed within a locking slot in the handle and the locking tab includes a cylindrical body including a first biasing member and a second biasing member configured to operate as a living spring to apply tension to a rod couplable to the intervertebral spacer. 